Year: 2013
Type: article
Abstract: The Atacama Cosmology Telescope has measured the angular power spectra of microwave fluctuations to arcminute scales at frequencies of 148 and 218 GHz, from three seasons of data. At small scales the fluctuations in the primordial Cosmic Microwave Background (CMB) become increasingly obscured by extragalactic foregounds and secondary CMB signals. We present results from a nine-parameter model describing these secondary effects, including the thermal and kinematic Sunyaev-Zel'dovich (tSZ and kSZ) power; the clustered and Poisson-like power from Cosmic Infrared Background (CIB) sources, and their frequency scaling; the tSZ-CIB correlation coefficient; the extragalactic radio source power; and thermal dust emission from Galactic cirrus in two different regions of the sky. In order to extract cosmological parameters, we describe a likelihood function for the ACT data, fitting this model to the multi-frequency spectra in the multipole range 500 < ℓ < 10000. We extend the likelihood to include spectra from the South Pole Telescope at frequencies of 95, 150, and 220 GHz. Accounting for different radio source levels and Galactic cirrus emission, the same model provides an excellent fit to both datasets simultaneously, with χ 2 /dof= 675/697 for ACT, and 96/107 for SPT. We then use the multi-frequency likelihood to estimate the CMB power spectrum from ACT in bandpowers, marginalizing over the secondary parameters. This provides a simplified `CMB-only' likelihood in the range 500 < ℓ < 3500 for use in cosmological parameter estimation.
Authors: J Dunkley, E Calabrese, J Sievers, G.E Addison, N Battaglia, E.S Battistelli, J.R Bond, S Das, M.J Devlin, R Dünner, J.W Fowler, M Gralla, A Hajian, M Halpern, M Hasselfield, A.D Hincks, R Hlozek, J.P Hughes, K.D Irwin, A Kosowsky, T Louis, T.A Marriage, D Marsden, F Menanteau, K Moodley, M Niemack, M.R Nolta, L.A Page, B Partridge, N Sehgal, D.N Spergel, S.T Staggs, E.R Switzer, H Trac, E Wollack
Institutions: University of Oxford, Princeton University, University of British Columbia, Carnegie Mellon University, Sapienza University of Rome, University of Toronto, Canadian Institute for Theoretical Astrophysics, Argonne National Laboratory, Lawrence Berkeley National Laboratory, University of California, Berkeley, University of Pennsylvania, Pontificia Universidad Católica de Chile, National Institute of Standards and Technology, Johns Hopkins University, Rutgers, The State University of New Jersey, University of Pittsburgh, University of California, Santa Barbara, University of KwaZulu-Natal, Cornell University, Haverford College, Stony Brook University, Goddard Space Flight Center
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Funders: National Science Foundation, National Aeronautics and Space Administration, Princeton University, University of Pennsylvania, Compute Canada, Government of Ontario, University of Toronto, Office of the Dean for Research, Princeton University, Science and Technology Facilities Council, Comisión Nacional de Investigación Científica y Tecnológica, FP7 Ideas: European Research Council
Awards: Fundamental Physics from the Cosmic Microwave Background, Gravitational Physics from the Cosmic Microwave Background, Collaborative Research with the Atacama Cosmology Telescope (ACT): Probing Fundamental Physics Through Observations of Cosmic Structure, Gravitational Physics from the Cosmic Microwave Background, G8085321155, ACTPol: The Atacama Cosmology Telescope with Polarization
OpenAlex ID: W2128317762